JPH05321246A - Inter-wall joining method for underground continuous wall - Google Patents

Abstract

PURPOSE:To enhance the transmitting ability of a partition wall for an intra- and extra-plane shearing force between unitary walls. CONSTITUTION:A mild steel bar cage 4 is provided where a partition plate is installed in the joint between a preceding wall 1 and a subsequent wall. wherein a mild steel bar joint 5 is protruded from the partition plate 14 of the cage 4, and concrete 6 is placed using this partition plate 14 as a form. Thus the preceding wall 2 is constructed. To construct the subsequent wall 2, on the other hand, a mild steel bar joint 8 of a mild steel bar cage 9 is joined with the mentioned joint 5 by the lap joint followed by placing of concrete 16. In this method of inter-wall joining for an underground continuous wall, the partition plate 14 consists of a plate 15 having uneven surface, and the joint between the preceding and subsequent walls 1, 2 is formed by the fit due to their unevenness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wall-to-wall joining method for underground continuous walls.

[0002]

2. Description of the Related Art Underground continuous walls are used as permanent underground outer walls of buildings and civil engineering structures, and their functions are as seismic walls, contralateral pressure walls against earth pressure, and foundation piles. In addition, since it is not possible to construct the outer walls of the four surrounding buildings at once in the underground continuous wall, several walls of unit width and thickness are constructed underground from the ground.

FIG. 7 shows the construction of such an underground continuous wall. The leading wall 1 is formed from a partition plate 3 of a reinforcing bar basket 4 in which a partition plate 3 as an iron plate form is incorporated at the joint with the trailing wall. First, the reinforcing bar joint 5 is projected. The concrete 6 cast on the side of the preceding wall 1 is stopped by this partition plate 3. The trailing wall 2 is provided with a reinforcing bar basket 9 provided with a reinforcing bar joint 8 at the joint with the preceding wall. The rebar joint 8 has a narrow width so as to enter the rebar joint 5.

After placing the concrete 6 of the preceding wall 1, the reinforcing bar basket 4 of the trailing wall 2 is placed in the excavation groove 10 and, although not shown, the concrete of the trailing wall 2 is placed. The reinforcing bar joint 5 and the reinforcing bar joint 8 to be wrapped are joined together. A shear connector 7 is provided on the partition plate 3 so as to project toward the leading wall 1 side and the trailing wall 2 side.

FIG. 8 shows a state when the front wall 1 is poured into concrete, and flanges 3a are provided at both ends of the partition plate 3. However, in order to prevent concrete from turning in from this flange 3a, If the concrete wraparound prevention sheet 11 is poured, and if the partition plate 3 alone does not have the strength to withstand the lateral pressure at the time of placing concrete, the backup material 12 and the backup pipe 13 that reinforce the opposite side are provided.
Are arranged and these are to be removed after the concrete is poured.

[0006]

The unit walls of the leading wall 1 and the trailing wall 2 as described above are required to transmit in-plane and out-of-plane shear forces and out-of-plane moments. The in-plane force and the out-of-plane force are transmitted only by the dowel action of the reinforcing bar or the shear connector 7 penetrating the partition plate 3. In this case, since the shear force is transmitted only by the dowel action, the shear deformation becomes large, and the allowable shear force is determined by the shear deformation. In general, it is said that "the ultimate shear strength of splicing is such that the shear deformation is 5 mm as shown by the broken line in Fig. 9" (Fig. 10 is an explanatory diagram showing the contents).

Therefore, when the shear deformation is large despite the large shear strength, the ultimate shear strength is determined by the deformation and becomes a small value.

It is an object of the present invention to provide a method for joining walls of continuous underground walls which can solve the above-mentioned disadvantages of the prior art and improve the ability to transmit in-plane and out-of-plane shear forces between unit walls. It is in.

[0009]

In order to achieve the above-mentioned object, the present invention is such that a leading wall has a reinforcing bar joint projecting from the partition plate of a reinforcing bar basket in which a partition plate is incorporated in a joint portion with a trailing wall. The partition wall is formed by pouring concrete into a formwork, and the trailing wall is formed by joining the reinforcing bar joint of the reinforcing bar basket to the reinforcing bar joint on the preceding wall side protruding from the partition plate with a lap joint, and then pouring the concrete. In the wall-to-wall joining method for the underground continuous wall to be installed and formed, a plate having an uneven surface is used as the partition plate, and the joining surfaces of the preceding wall and the trailing wall are both fitted with the uneven surface. Is the gist.

[0010]

According to the present invention, by using the plate having the uneven surface, the shear deformation caused by the shearing force acting between the partition plates as shown in FIG. 9 uses the conventional planar partition plate. It is significantly smaller than. Also, the ultimate shear strength (proof strength at a deformation of 5 mm) is significantly larger than that of the conventional one.

When a shearing force acts between the partition plates, the unevenness is displaced as shown in FIG. Due to the displacement, the irregularities open to the left and right, and a tensile force acts on the joined reinforcing bars. The tensile force becomes a compressive force between the irregularities, and the shearing friction force increases due to the compressive force.
Due to the increase in the shear friction force, the ultimate shear strength at the time of deformation of 5 mm is significantly increased. However, the fracture resistance does not increase so much.

[0012]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a method 1 of joining underground continuous walls according to the present invention.
In the cross-sectional plan view showing the embodiment, the same components as those of the conventional example shown in FIG. 7 are designated by the same reference numerals.

As in the prior art example, the leading wall 1 has the reinforcing bar joint 5 projecting from the partition plate 14 of the reinforcing bar basket 4 in which the partition plate 14 as a form is incorporated at the joint with the trailing wall. In the present invention, the partition plate 14 incorporates an uneven plate 15 having an uneven surface. As in the conventional case, flanges 14a are provided on both side ends of the partition plate 14, and the central portion of the web 14b thereof is omitted, and this portion is closed by the uneven plate 15 made of a steel plate or vinyl chloride.
As the uneven shape of the uneven plate 15, it is conceivable that the entire shape is corrugated, or that the uneven projections are scattered as shown in FIG.

A connecting rod 17 is bridged between the ends of the leading wall 1 of the flange 14a of the partition plate 14.

As a first embodiment, when the uneven plate 15 can withstand the lateral pressure of the concrete 6 which is cast with a thick steel plate, the concrete 6 of the preceding wall 1 is cast as in the conventional example. After that, the reinforcing bar basket 4 on the trailing wall 2 is excavated.
It is arranged inside 10, and the concrete of the trailing wall 2 is cast, and the uneven plate 15 is embedded as it is between the concretes 6 and 16.

In this way, the leading wall 1 and the trailing wall 2 are joined together by the reinforcing bar joint 5 and the reinforcing bar joint 8 to be wrapped.

Next, as a second embodiment, the concavo-convex plate 15 is made of a steel plate or vinyl chloride, and the concrete 6 to be placed
The case where the device does not have the strength to withstand the lateral pressure of will be described. In this case, the backup iron plate 18 is arranged on the back side of the uneven plate 15 (on the trailing wall 2 side), but the upward hook-shaped dowel receiving bracket 19 is provided on the web 14b of the partition plate 14, while the backup iron plate 18 side is arranged. A dowel 20 with a steel bar is projected on the end,
The dowel 20 is hooked by the dowel receiving bracket 19.

Although the uneven plate 15 is joined at its upper and lower ends by the connecting plate 21, the size of the backup iron plate 18 is approximately between the webs 14b in the horizontal direction and between the connecting plates 21 in the vertical direction. Size. Further, as shown in FIG. 5, a lower end stopper 22 is fixed to the tie plate 21 by welding, and the lower end of the backup iron plate 18 is locked to the lower end stopper 22 for backup.

When the reinforcing bar basket 4 is set, the backup iron plate 18 is also provided, and the presence of the backup iron plate 18 enables the uneven plate 15 to withstand the lateral pressure of the concrete 6 to be placed.

When the concrete 6 is hardened, the backup iron plate 18 can be pulled out with a wire or the like so that the dowel 20 can be removed from the dowel receiving bracket 19 and only the backup iron plate 18 can be removed leaving the uneven plate 15.

After that, the reinforcing bar basket 4 of the trailing wall 2 is excavated in the excavation groove 10
Inside, the concrete of the trailing wall 2 is placed, and the uneven plate 15 is embedded between the concretes 6 and 16.
In this way, the leading wall 1 and the trailing wall 2 are joined to each other by the reinforcing bar joint 5 and the reinforcing bar joint 8 to be wrapped.

[0022]

As described above, the wall-to-wall joining method for underground underground walls of the present invention is capable of improving in-plane and out-of-plane shear force transmission capability between unit walls in a partition plate portion. Is.

[Brief description of drawings]

FIG. 1 is a cross-sectional plan view showing an embodiment of an inter-wall joining method for underground continuous walls according to the present invention.

FIG. 2 is a view taken along the line AA of FIG.

FIG. 3 is a cross-sectional plan view when a backup iron plate is provided showing an embodiment of a method for joining walls of an underground continuous wall of the present invention.

FIG. 4 is a view taken along the line BB of FIG.

5 is a view taken along the line CC of FIG.

FIG. 6 is an explanatory diagram showing the operation of the present invention.

FIG. 7 is a cross-sectional plan view showing a conventional example.

FIG. 8 is a cross-sectional plan view showing another conventional example.

FIG. 9 is a graph showing the relationship between shear force and shear deformation.

FIG. 10 is an explanatory diagram showing the relationship between shear force and shear deformation.

[Explanation of symbols]

1 ... Leading wall 2 ... Trailing wall 3 ... Partition plate 4 ... Reinforcing bar basket 5 ... Reinforcing bar joint 6 ... Concrete 7 ... Shear connector 8 ... Reinforcing bar joint 9 ... Reinforcing bar basket 10 ... Excavation groove 11 ... Concrete wrapping sheet 12 ... Backup material 13 ... Backup pipe 14 ... Partition plate 14a ... Flange 14b ... Web 15 ... Rough plate 16 ... Concrete 17 ... Connecting rod 18 ... Backup iron plate 19 ... Dowel receiving bracket 20 ... Dowel 21 ... Connecting plate 22 ... Bottom stopper metal fitting

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akira Miyata 2-19-1 Tobita, Chofu-shi, Tokyo Kashima Construction Co., Ltd. Technical Research Institute (72) Inventor Kazuo Suzuki 1-2-7 Moto-Akasaka, Minato-ku, Tokyo Kashima Construction Co., Ltd.

Claims (1)

[Claims] 1. The leading wall is a reinforcing bar basket in which a partition plate is incorporated in a joint portion with a trailing wall, the reinforcing bar joint is projected first from the partition plate, and concrete is cast using the partition plate as a formwork. Formed, the trailing wall, by joining the reinforcing bar joint of the reinforcing bar basket to the reinforcing bar joint on the side of the preceding wall protruding from the partition plate with a lap joint, in the wall-to-wall joining method of the continuous underground wall formed by placing concrete The partitioning plate is a plate having an uneven surface, and the joining surface of the leading wall and the trailing wall is formed by fitting the uneven surface on both surfaces, and the wall-to-wall joining method for a continuous underground wall.